The art of drycleaning soiled articles of clothing is old and well established. In the commercial process of drycleaning, soiled garments are agitated in an organic solvent contained in a perforated cylinder to remove oil, grease stains and particles of soil. Typically, small quantities of water and additives are introduced into the organic solvent to help remove water soluble soil, such as sugar and salt stains, to dissipate static charges which build upon the garments as they are tumbled during the drycleaning process and to provide detergency, softening, brightening, etc. According to known practice, the drycleaning solvent is repeatedly recirculated through a filter to remove the soil particles from the organic solvent. This treatment generally lasts from 10 to 30 minutes. After this cleaning phase, the organic solvent is drained from the cylinder and the garments are extracted or spun to remove the bulk of the organic solvent from the wet load. The residual organic solvent and moisture contained by the garments are then removed by passing a current of warm air either through a rotating cylinder containing the garments or, in the case of fragile garments, through a drying cabinet.
Even though the practice of drycleaning soiled garments is well established, the introduction of drycleaning additives into drycleaning machines has long been a problem for the drycleaning industry for many reasons. First, it is standard practice in the industry to introduce the additives including water by hand. The products must be poured or pumped from the bulk shipping containers into a measuring cup. The contents are then transferred to the drycleaning units. Since the additives are introduced into the drycleaning solvents by hand, it is necessary for the drycleaning operators to conduct extensive calculations from recorded data or perform sensitive chemical titration procedures to determine exactly how much additive should be added to ensure effective drycleaning. Unfortunately and all too often during the manual process, such additives are either spilled which is wasteful and messy or added in inconsistent and imprecise amounts due to errors in the calculations or the chemical titration procedures. To help overcome these problems, the drycleaning industry has resorted to elaborate mechanical injection systems. Such systems, however, are not without their drawbacks. They require expensive upkeep and are often inaccurate, i.e., they add too little or too much product.
A second problem associated with introducing drycleaning additives into a drycleaning system is concerned with the viscosities of the drycleaning additives in their concentrated forms. Since drycleaning additives are typically in the form of very viscous liquids or grease, it is necessary to lower their viscosities so that they can be easily injected or poured into the drycleaning units. Most commercial drycleaning additives therefore contain added solvents and chemicals to produce final products that have viscosities which make them more convenient and easy to use by the drycleaning personnel. Unfortunately, the added solvents and chemicals are not without their drawbacks. They are often a hindrance to the cleaning results since they contaminate the drycleaning solvents, serve no cleaning purpose, and often impart undesirable odors to the cleaned and finished garments. Moreover, such solvents and chemicals are toxic to man and/or hazardous to the environment. During the process, the drycleaning personnel are at risk at all times to the toxic effects of such solvents and chemicals due to vapor inhalation and skin and eye contact. Spill hazards are also at risk during the process in view the extensive handling of these products by the drycleaning personnel. To further complicate matters, in some states, the empty bulk containers for these products are considered hazardous waste materials and therefore must be disposed of in accordance with proper procedures.
A further problem associated with such introduction is concerned with the stability of the drycleaning additives. Because drycleaning additives are typically purchased and used in bulk, it is very difficult to protect such drycleaning products from external contamination, oxidation, moisture and the like.
Although attempts have been made in the past to reduce the problems associated with the introduction of drycleaning additives into drycleaning solvents during the cleaning operation, e.g., the installation of mechanical injection devices, to-date these efforts have achieved only limited success for the reasons states above. It is therefore desirable to provide the drycleaning industry with a clean, unique, reliable and inexpensive method for introducing drycleaning additives into drycleaning solvents in precise and consistent quantities without the above-mentioned disadvantages and drawbacks.